The objective of this proposal is to examine the characteristics of surface active biomaterials in the head and neck area, specifically in the ear. Our thesis is that the biomaterials interface is dynamic, e.g., a material can alter the physiological environment and vice versa. Therefore, control of the surface chemistry of the biomaterial can be used to control the physiologic interface. With control of this interface, bone bonding properties of bioglass have been developed at the University of Florida over the last seven years. Exploration of the applications of this material to current designs of middle ear prostheses will permit evaluation of the material in this environment and will permit design evolution of prostheses in the search for more effective reconstructive techniques. Past experience with the use of this material in both closed soft and hard tissue environments in experimental animals and in the oral cavity in a contaminated implant has encouraged us to expect a significant improvement over current "inert" protheses. Our research protocol calls for implantation of block substance in the ear with examination of both soft and hard tissue responses. Implantation of material as ossicular chain components with analysis of induced bone growth and finally, bioglass based materials designs will be tested in the form of current prostheses to permit final animal analysis prior to human applications. Electron microprobe analysis and scanning electron microsocpy with energy dispersive X-ray analysis will be conducted upon the interface between bone and the bioglass implants to measure thickness of the bonding layers. Comparison of changes in thickness of the bonding layers with time sequence studies already conducted in rat and sub-human primates will be used to establish the stability of the bonding junction, in the ear environment.